#include "postgres.h"

#include "fmgr.h"
#include "plpython.h"
#include "ltree.h"

PG_MODULE_MAGIC;

extern void _PG_init(void);

/* Linkage to functions in plpython module */
#if PY_MAJOR_VERSION >= 3
typedef PyObject *(*PLyUnicode_FromStringAndSize_t) (const char *s, Py_ssize_t size);
static PLyUnicode_FromStringAndSize_t PLyUnicode_FromStringAndSize_p;
#endif


/*
 * Module initialize function: fetch function pointers for cross-module calls.
 */
void
_PG_init(void)
{
    /* Asserts verify that typedefs above match original declarations */
#if PY_MAJOR_VERSION >= 3
    AssertVariableIsOfType(&PLyUnicode_FromStringAndSize, PLyUnicode_FromStringAndSize_t);
    PLyUnicode_FromStringAndSize_p = (PLyUnicode_FromStringAndSize_t)
        load_external_function("$libdir/" PLPYTHON_LIBNAME, "PLyUnicode_FromStringAndSize",
                               true, NULL);
#endif
}


/* These defines must be after the module init function */
#define PLyUnicode_FromStringAndSize PLyUnicode_FromStringAndSize_p


PG_FUNCTION_INFO_V1(ltree_to_plpython);

Datum
ltree_to_plpython(PG_FUNCTION_ARGS)
{
    ltree       *in = PG_GETARG_LTREE(0);
    int            i;
    PyObject   *list;
    ltree_level *curlevel;

    list = PyList_New(in->numlevel);

    curlevel = LTREE_FIRST(in);
    for (i = 0; i < in->numlevel; i++)
    {
        PyList_SetItem(list, i, PyString_FromStringAndSize(curlevel->name, curlevel->len));
        curlevel = LEVEL_NEXT(curlevel);
    }

    PG_FREE_IF_COPY(in, 0);

    return PointerGetDatum(list);
}
